Reaktion #4445

Reaktionsgleichung

α-bromo-4-acetylpyridine hydrobromide

potassium thiocyanate

hydrochloric acid

water

→

2-hydroxy-4-(4-pyridyl)thiazole

Lösungsmittel

ethanol

Reaktionsbedingungen

Aufarbeitung

1. 1
   Temperaturwas heated
2. 2
   Temperaturto reflux for two hours
3. 3
   Temperaturreflux
4. 4
   TemperaturAfter cooling
5. 5
   Filtrationthe crystallized solid was collected by filtration
6. 6
   Waschenwashed with ethanol
7. 7
   Sonstigeto obtain
8. 8
   Filtrationafter filtration
9. 9
   Sonstigedrying

Vorschrift

A mixture of α-bromo-4-acetylpyridine hydrobromide (140.0 g, 0.50 mol) and potassium thiocyanate (53.4 g, 0.55 mol) in absolute ethanol (1500 mL) was heated to reflux for two hours. To the resulting mixture was added concentrated hydrochloric acid (250 mL) and water (500 mL) and reflux continued for five hours. After cooling, the crystallized solid was collected by filtration and washed with ethanol. The resulting material was suspended in water and neutralized with aqueous sodium bicarbonate to obtain, after filtration and drying, 2-hydroxy-4-(4-pyridyl)thiazole 39.0 g, 44%). mp. 250° C.

Quelle